db.students.insertMany([
  { id: 1, name: 'Ryan', gender: 'M' },
  { id: 2, name: 'Joanna', gender: 'F' },
    {id:3,name:'Sreejith',gender:'M'}
]);
// db.students.find({ gender: 'F' });
// db.students.aggregate([
//     {$group:{_id:"$gender",count:{$sum:1}}}
// ])